Physics & Tech Calculator – Binary Converter, Ohm’s Law, Resistor Code, Big-O, Password Strength

Ohm’s Law Calculator

Enter any two values; leave the one you want to compute blank.

Resistor Color Code Decoder

Select number of bands and colors. Tolerance and multiplier applied automatically.

Big-O Complexity Estimator

Values shown in human-friendly scientific notation when large.

Password Entropy Calculator

Type a password or choose length & charset to estimate bits of entropy and guess time.

Estimated attacker guesses/sec: 1 billion (1×10⁹). Displayed times are approximate.